1. Field
The described technology relates generally to an organic light emitting diodes (OLED) display.
2. Description of Related Technology
An organic light emitting diodes display (OLEDD) includes a plurality of organic light emitting elements (OLED's) each respectively comprising an anode that is a hole injection electrode, an organic light emitting layer, and a cathode that is an electron injection electrode. Each organic light emitting element emits light due to photon energy generated when an exciton generated by combining an electron and a hole in the organic emission layer falls from an exited state to a ground state. The organic light emitting diodes display (OLEDD) displays a predetermined image by controlling the respective light emissions of its organic light emitting elements. Organic light emitting diodes (OLED's) may be degraded by external factors such as exposure to external moisture and oxygen, or ultraviolet (UV) rays. Accordingly, the packaging encapsulating the organic light emitting diode (OLED) is important, and the organic light emitting diode (OLED) may be encapsulated by an encapsulating substrate made of a metal or a glass.
Often, a touch panel is provided as an input device of the organic light emitting diodes display (OLEDD). The touch panel inputs information by being directly contacted on a screen thereof by a finger or a pen, and depending on the method of sensing the contacted portion, the touch panel may be classified into a resistive type of sensing where the contacted position is determined by a voltage gradient in a state that electrodes are formed at an upper plate or a rear plate and a DC voltage is applied, and a capacitive type of sensing a position where a voltage change of the upper and rear plates according to the contact is generated in a state that an equipotential is formed on a conductive layer.
Particularly, in the touch panel of the capacitive type, a plurality of Tx (transmission) wires extending in a horizontal direction and a plurality of Rx (receiving) wires extending in a vertical direction are formed on an encapsulating substrate. However, as resolutions increase, additional Tx wires and Rx wires must be formed on the encapsulating substrate of this type of touch panel such that the number of manufacturing steps needed during mass production is increased and a thickness of the touch panel portion increases.
To solve this problem, an ICTA (In Cell TSP AMOLED) structure separating the cathode to use as each Tx wire has been developed. However, in this case, an RC delay of the Tx wire may not be well controlled such that the RC delay of the Tx wire is determined according to a size of the organic light emitting diodes display (OLEDD), according to a resolution of the Tx wires and the Rx wires, and according to a material of the cathode. Accordingly, when a touch characteristic is deteriorated by the resistance of the Tx wires or a parasitic capacitance, the material of the cathode must be changed, or a thickness of the organic layer or a line width of a driving voltage layer (ELVDDL) must be reduced, such that there is a drawback that factors affecting the image display must be amended through estimation over a long period of time.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the here disclosed technology and as such, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.